Question

我是ios编程的新手; 我编写了一个应用程序以在UITableView中显示食谱列表，在选择一行后，行标题将解析为详细视图中的UITextField。

问题：我可以做些什么来保存详细视图中的标题更改到表视图（我使用故事板）？

这是我的代码：

NViewController.m：

- (void)viewDidLoad
{
    [super viewDidLoad];

    recipes = [NSArray arrayWithObjects:@"Egg Benedict", @"Mushroom Risotto", @"Full Breakfast", nil];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"RecipeCell";
    MyTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    if (cell == nil) {
        cell = [[MyTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
    }
    cell.lblName.text = [recipes objectAtIndex:indexPath.row];
    return cell;
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"showRecipeDetail"]) {
        NSIndexPath *indexPath = [self._tableView indexPathForSelectedRow];
        NDetailViewController *destViewController = segue.destinationViewController;
        destViewController.selectedRowTitle = [recipes objectAtIndex:indexPath.row];
    }
}

NDetailViewController.m：

@interface NDetailViewController ()
@property (weak, nonatomic) IBOutlet UITextField *txtDetailText;

@end

@implementation NDetailViewController

@synthesize selectedRowTitle;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization

    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.txtDetailText.text = selectedRowTitle;
}

Answer 1

在NViewController中，添加NSIndexPath以保存：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:@"showRecipeDetail"]) {
    NSIndexPath *indexPath = [self._tableView indexPathForSelectedRow];
    NDetailViewController *destViewController = segue.destinationViewController;
    destViewController.selectedRowTitle = [recipes objectAtIndex:indexPath.row];

    // need to save this indexPath to update when textfield is changed. Because indexPath maybe change if data changes, I think you should choose another field (like KEY, distingue objects)
    destViewController.indexPath = indexPath;
    destViewController.delegate = self;
}
}

-(void)changeTextFieldWithIndexPath : (NSIndexPath*)indexPath content:(NSString*)content;
{
 // you update indexPath to row, and reloadTable
}

NDetailViewController.h：

@protocol NDetailViewControllerDelegate <NSObject>
-(void)changeTextFieldWithIndexPath : (NSIndexPath*)indexPath content:(NSString*)content;
@end

@interface NDetailViewController : ViewController
@property (nonatomic, weak) id<NDetailViewControllerDelegate> delegate;
@end

NDetailViewController.m：当textfiled更改值时，我的方法只是一个例子：

- (void) whenContentOfTextFieldChanged
{
[self.delegate changeTextFieldWithIndexPath:indexPath content:@"content which textfield is changed"];
}

Answer 2

假设您正在使用UISplitview控制器，您可以通过[self.splitviewcontroller.viewcontrollers objectatindex：0]访问masterview并在其上调用已定义的方法。

您也可以使用通知传递数据请查看此答案以获取通知示例：How to pass object with NSNotificationCenter

将数据解析回viewcontroller

2 个答案: